Maybe that's when bad scripts are written, when you choose the theme first. I consider that I've something to say when I've thought of a person, a moment, a single beat of the heart, that I think is true and interesting, and therefore should be seen.

I saw the Fall of Troy! World War Five! I was pushing boxes at the Boston Tea Party! Now I'm gonna die in a dungeon.... [disgustedly] in Cardiff!

Fun, that's the word I keep on using. That's the word I worry about when other writer's scripts get too dark. Optimistic. Fun. And to be optimistic and have fun there's got to be a darkness there. I think that's a very British attitude.

Buffy the Vampire Slayer showed the whole world, and an entire sprawling industry, that writing monsters and demons and end-of-the-world is not hack-work, it can challenge the best. Joss Whedon raised the bar for every writer - not just genre or niche writers, but every single one of us.

My God, that scene in Monster Inc. where the monsters realise that their entire world is founded on hurting children -look at that for a change! Two galumphing cartoon characters making a shattering realisation about their world and their role in sustaining it. A truly epic moment. It's stunning.

In the end I sort of though we created a companion who was so alive and dynamic and so wedded to the doctor that you’d need a whole universe to contain her in. The only way to get rid of her is to send her into a parallel world from which she can never return; otherwise she would stay with the doctor forever.

I hate the idea that I have to represent any particular section of society; I just write good telly, that's all.